The Defense Meteorological Satellite Program (DMSP) Thermal Imager

The Defense Meteorological Satellite Program satellites carry two IR sensing instruments for collecting information of meteorological significance on a daily basis. One of these instruments, designated the Primary Sensor, is a high resolution wide-angle scanning radiometer which provides both visual ("albedo") and infrared (temperature) information to the Air Force Global Weather Central data base. The second is an infrared sounder which measures the IR energy in sixteen narrow spectral bands within a well defined field-of-view for discrete time intervals. The data from these sensors are computer processed to extract meteorological information such as cloud cover, cloud height, vertical temperature profiles, vertical relative humidity profiles and atmospheric ozone content measurements. This paper describes some of the infrared technology incorporated in the Thermal Imager and how it is combined into the Primary Sensor system which routinely collects the vast amounts of information which form a significant portion of the military global weather data base.